Expansion of the genus Massinium (Holothuroidea: Thyonidae) to the American continent and description of a new species / Expansión del género Massinium (Holothuroidea: Thyonidae) al continente americano y descripción de una nueva especie

Introduction: The genus Massinium includes 11 species, most from the Indo Pacific Ocean, and had not previously being reported from the American continent. Objective: To present the new record of the genus Massinium and describe a new species of this genus. Methods: Material collection was done by SCUBA-diving to depths of a maximum of 9 m. Results: Massinium ocumichoensis sp. nov. is described from seven specimens that extends the range of the genus to the American continent (Guerrero, Michoacan and Jalisco, Mexico). The new species lives in sandy-rocky substrata, from 2 to 16 m deep. It is distinguished from its congeneric species by a combination of morphological characters: mid-dorsal slightly bigger pseudobuttons (40-60 μm), and tables in the body wall. A taxonomic key for distinguishing the species of Massinium is provided. Conclusions: The geographic range of the genus Massinium is extended to the Mexican Pacific with M. ocumichoensis sp. nov.

Introducción : El género Massinium incluye 11 especies, la mayoría del Océano Indo-Pacífico, y no se había reportado previamente en el continente americano. Objetivo: Presentar el nuevo registro del género Massinium y describir una nueva especie de este. Métodos: La recolección de material se realizó mediante buceo a una profundidad máxima de 9 m. Resultados: Massinium ocumichoensis sp. nov. se describe a partir de siete ejemplares que extiende el rango de distribución del género al Continente Americano (Guerrero, Michoacán y Jalisco, México). La nueva especie vive en sustratos arenosos-rocosos, de 2 a 16 m de profundidad. Se distingue de sus especies congenéricas por una combinación de caracteres morfológicos: pseudobotones de la zona dorsal media ligeramente más grandes (40-60 μm) y tablas en la pared del cuerpo. Se proporciona una clave taxonómica para distinguir las especies de Massinium. Conclusiones: El rango geográfico del género Massinium se extiende al Pacífico mexicano con M. ocumichoensis sp. nov.

Biodiversidad de ofiuroideos (Echinodermata: Ophiuroidea) del talud de la Península de Yucatán, México

Introduction: The Ophiuroidea class is the most diverse of the Phylum Echinodermata, with 2 064 described species, which can be found from intertidal zones to abyssal depths, but the fauna of Yucatan peninsula needs more study. Objective: To describe the diversity of ophiuroids in the Yucatan continental slope. Methods: Information was compiled from four oceanographic surveys carried out in August 2005, June 2007 (BIOREPES 1 and 2: BRP1 and BRP2), April 2011 and August 2014 (COBERPES 2 and 6: CBP2 and CBP6). The specimens were obtained by trawling with a shrimp net in soft substrates and with a skimmer-type trawl dredge at a depth range of 200 to 1 071 m off the states of Yucatán and Quintana Roo, Mexico. Results: We found members of two superorders, five orders, six suborders, five superfamilies, 18 families, 28 genera and 43 species. Conclusions: The northeast zone Yucatan Peninsula has at least 43 species, of which 19 are new records for the area.

Introducción: La clase Ophiuroidea es la más diversa del Phylum Echinodermata, con 2 064 especies descritas, que se pueden encontrar desde zonas intermareales hasta profundidades abisales, pero la fauna de la península de Yucatán necesita más estudio. Objetivo: Describir la diversidad de ofiuroideos en el talud continental de Yucatán. Métodos: Se recopiló información de cuatro estudios oceanográficos llevados a cabo en agosto de 2005, junio de 2007 (BIOREPES 1 y 2: BRP1 y BRP2), abril de 2011 y agosto de 2014 (COBERPES 2 y 6: CBP2 y CBP6). Los especímenes se obtuvieron mediante la pesca de arrastre con una red camaronera en sustratos blandos y con una draga de arrastre tipo skimmer en un rango de profundidad de 200 a 1 071 m frente a los estados de Yucatán y Quintana Roo, México. Resultados: Encontramos miembros de dos superórdenes, cinco órdenes, seis subórdenes, cinco superfamilias, 18 familias, 28 géneros y 43 especies. Conclusiones: La zona noreste de la Península de Yucatán tiene al menos 43 especies, de las cuales 19 son nuevos registros para el área.

Ontogenetic variation of the odontophore of Luidia superba (Asteroidea: Paxillosida) and its taxonomic implications

Introduction: The sea star odontophore is the structure positioned between the paired oral ossicles, with which they articulate through proximal and distal processes. The internal anatomy structures may be used as taxonomic characters for a precise differentiation between species, so it is necessary to describe the structures variation throughout growth. Objective: To describe the odontophore shape and variation of Luidia superba A. H. Clark, 1917 from specimens of the Gulf of California deposited in the Echinoderm National Collection, ICML UNAM. Methods: A total of 735 specimens were examined to describe the external characters, from which 55 selected specimens, within a range of R = 14 mm and R = 210 mm, were dissected to extract the odontophores and analyzed with geometric morphometrics. Results: Scanning electronic microscopy (SEM) images of the odontophores showing the variations in shape throughout growth are presented. Differences in shape between size groups were confirmed with a Canonical Variables Analysis (P < 0.05). Conclusions: There are three main groups in this size ranges where specialization of the stereom can be observed through the ontogenetic series; the variation in shape of the odontophore shown here is a precedent for the use of internal anatomy as new taxonomic characters of identification.

Introducción: El odontóforo es la estructura posicionada entre las placas orales pareadas con las que se articula a través de procesos proximales y distales. Las estructuras de la anatomía interna se pueden usar como caracteres taxonómicos para la diferenciación más precisa entre especies, por lo que es necesario describir la variación de las estructuras a lo largo del crecimiento. Objetivo: Describir la forma y la variación del odontóforo de Luidia superba A. H. Clark, 1917 de ejemplares del Golfo de California depositados en la Colección Nacional de Equinodermos, ICML UNAM. Métodos: Se revisaron un total de 735 ejemplares para describir los caracteres externos y de las cuales se seleccionaron 55 ejemplares, dentro de un intervalo de R = 14 mm a R = 210 mm, de los cuales se extrajeron los odontóforos y fueron analizados utilizando morfometría geométrica. Resultados: Se presentan imágenes de microscopía electrónica de barrido (MEB) de los odontóforos que muestran las variaciones de la forma durante el crecimiento. Se confirmaron diferencias significativas de la forma entre los grupos de tallas mediante un CVA (p< 0.05). Conclusiones: Se observa especialización del estereoma a lo largo de la serie ontogenética; la variación en la forma del odontóforo aquí mostrada es precedente para el uso de estructuras de la anatomía interna como nuevos caracteres de identificación.

Morphological comparison of Astropecten cingulatus and a new species of Astropecten (Paxillosida, Astropectinidae) from the Gulf of Mexico.

Astropecten cingulatus is a conspicuous species, which displays a large superomarginal plate series on the abactinal surface. Herein we describe a new species from off the Texas coast that shows the superficial appearance of A. cingulatus, including these large superomarginal plates, but with armature differing from that of typological A. cingulatus. This species shows the actinal surface of the inferomarginal plates without the squamules present on A. cingulatus. In addition, the adambulacral plates possessed but a single central large spine surrounded by a circle of spines rather than spine rows. The abactinal paxillar region was also very narrow. Statistical analysis of these and other morphological characters showed the specimens differed significantly from those of A. cingulatus. The regression of the slope of R:SM# vs. R was significant but the intercept was not. Therefore the two species are indistinguishable at small sizes based on R:SM. Compared to known Atlantic Astropecten spp. these observed characters warrant the description of a new species, Astropecten karankawai, for the specimens from off the coasts of Texas and Mexico.

Lower Cretaceous (Albian) Asteroidea (Echinodermata) from Tepexi de Rodriguez, Puebla, Mexico / Asteroidea (Echinodermata) del Cretácico inferior (Albaniano) de Tepexi de Rodríguez, Puebla, México

Abstract Seven asteroids are described from the Tlayua quarries (18° 35´ N - 97° 56´ W), recovered from the Middle Member of the Tlayua Formation. Tlayua quarries are 94 km southeast of Puebla and 2 km northeast of the town of Tepexi de Rodriguez in the Eastern part of central Mexico. The Middle Member is fossiliferous and composed mainly of a micritic lithographic limestone with layers having packs that consist of as much as 30 % hematite. The fossils are confined to these iron rich layers. These Middle Member are about 28 m thick. Due to the abundance, variety and conservation of its paleobiota, the Tlayua quarry is one of the most important fossiliferous localities from North America's Cretaceous. About 5 000 samples of invertebrate and vertebrate fossils have been collected from this locality and have been studied. The seven specimens belong to the Cretaceous strata and are believed to be of Lower Cretaceous (Albian) age. The asteroids described are referred to the genus Astropecten, Plutonaster, Tamaria and Echinaster. This is the first report of Cretaceous asteroids for Mexico. Rev. Biol. Trop. 63 (Suppl. 2): 7-15. Epub 2015 June 01.

Resumen Siete asteroideos son descritos de las canteras de Tlayua (18° 35´N - 97° 56´ W), recuperados del miembro medio de la formación Tlayua. Las canteras de Tlayua se encuentran a 94 km al sureste de Puebla, y a 2 km de noreste del pueblo de Tepexi de Rodriguez en la parte este del centro de México. El miembro medio es fosilífero y está compuesto principalmente de basamentos micríticos litográficos con capas con grupos que consisten de la menos 30 % de hematita. Los fósiles están confinados a estas ricas capas en hierro. Estos miembros medios poseen un espesor de aproximadamente 28 m. Debido a la abundancia, variedad y conservación de su paleobiota, la cantera de Tlayua es una de las localidades fosilíferas más importantes del Cretácico de Norte América. Cerca de 5 000 muestras de fósiles de invertebrados y vertebrados han sido colectadas y estudiadas de esta localidad. Las siete especies pertenecen al estrato del Cretácico y se cree que pertenecen a la edad del Cretácico inferior (Albaniano). Los asteroideos descritos se refieren a los géneros Astropecten, Plutonaster, Tamaria y Echinaster. Este es el primer registro de asteroideos del Cretácico para México.

Caraterización citogenética del pez tropical de agua dulce Parachromis managuensis (Pisces: Cichlidae) / Citogenetic characterization of the tropical freshwater fish Parachromis managuensis (Pisces: Cichlidae)

To describe the cytogenetics of the jaguar cichlid fish Parachromis managuensis, we collected eight males and 13 females in Villahermosa, Tabasco, México. The specimens were processed with standard cytogenetic techniques (slightly modified), and high quality fields of chromosomes in mitosis and meiosis were obtained; 14 of these fields were analyzed by meristics and statistics methods. The specimens presented a diploid modal number of 2n=48 chromosomes, which is similar to the number reported for others Central American cichlids; five pairs were submetacentric-metacentrics(biarmed)and 19 were subtelocentric-telocentric (uni-armed), giving a fundamental number (NF)of 58.The haploid number was confirmed by counting meiotic fields in metaphase I. There was not evidence of heteromorphism: sexual chromosomes were not identifiable.

Para contribuir con el ordenamiento de las especies de la familia Cichlidae, se realizó el estudio citogenético de la mojarra pinta Parachromis managuensis. Fueron utilizados veintiún organismos, ocho machos y trece hembras,colectados en Villahermosa, Tabasco, México. Los especímenes se procesaron por técnicas citogenéticas convencionales (con ligeras modificaciones). Se obtuvieron campos mitóticos y meióticos de buena calidad, de los que fueron seleccionados catorce cariotipos para ser analizados merística y estadísticamente. Los especímenes presentaron número modal diploide de 2n=48 cromosomas, similar al reportado para otros cíclidos neotropicales. Cinco pares fueron cromosomas metacéntricos-submetacéntricos (birrámeos) y 19 pares cromosomas subtelocéntricos-telocéntricos (monorrámeos),con número fundamental (NF) de 58 brazos.El número haploide se ratificó por conteo de campos meióticos en metafase I. Los campos mitóticos observados y los cariotipos de machos y hembras no presentaron evidencias heteromórficas para identificar cromosomas sexuales.

[Citogenetic characterization of the tropical freshwater fish Parachromis managuensis (Pisces: Cichlidae)]. / Caraterización citogenética del pez tropical de agua dulce Parachromis managuensis (Pisces: Cichlidae).

To describe the cytogenetics of the jaguar cichlid fish Parachromis managuensis, we collected eight males and 13 females in Villahermosa, Tabasco, México. The specimens were processed with standard cytogenetic techniques (slightly modified), and high quality fields of chromosomes in mitosis and meiosis were obtained; 14 of these fields were analyzed by meristics and statistics methods. The specimens presented a diploid modal number of 2n = 48 chromosomes, which is similar to the number reported for others Central American cichlids; five pairs were submetacentric-metacentrics (biarmed) and 19 were subtelocentric-telocentric (uni-armed), giving a fundamental number (NF) of 58. The haploid number was confirmed by counting meiotic fields in metaphase I. There was not evidence of heteromorphism: sexual chromosomes were not identifiable.

[Catalogue of neritic-benthonic echinoderms (Echinodermata: Crinoidea, Echinoidea, Holothuroidea) from the Cuban Archipelago]. / Catálogo de los equinodermos (Echinodermata: Crinoidea, Echinoidea, Holothuroidea) nerítico-bentónicos del Archipiélago Cubano.

This is an updated taxonomic catalogue of neritic-benthonic Echinodermata (Crinoidea, Echinoidea, Holothuroidea) from Cuba, that includes locality, range, habitat and depth where each species is found. The species list is based on the collections of the Oceanology Institute; Havana, and the "Felipe Poey" Museum (Havana University) Specimens for those collections were captured by a variety of field techniques, narcotized with Cloral hydrate, fixed in formalin and stored in 70-80% alcohol. A total of 53 species were recorded (eight Crinoids, 22 Echinoids and 23 Holothuroids), in 37 genera, 19 families and 12 orders. Ocnus suspectus (Ludwig, 1874) and Phyllophorus (Urodemella) occidentalis (Ludwig, 1885) are new records for Cuban waters.

[Echinoderms (Echinodermata) from the Mexican waters of the Gulf of Mexico]. / Equinodermos (Echinodermata) de las aguas mexicanas del Golfo de México.

We present a systematic list of the echinoderms from Gulf of Mexico's Mexican waters based on specimens of the Colecci6n Nacional de Equinodermos, Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Aut6noma de México and the National Museum of Natural History, Smithsonian Institution, Washington, D.C. This list reveals an important echinoderm biodiversity present in the Gulf of Mexico, where five of the six echinoderm classes are represented. A total of 209 echinoderm species is recorded, distributed in 129 genera, 63 families and 25 orders. 31 new records for the Gulf of Mexico are presented: Asteroidea (16), Ophiuroidea (nine), Echinoidea (one) and Holothuroidea (five).

[Echinoids (Echinodermata: Echinoidea) from the Gulf of Mexico]. / Equinoideos (Echinodermata: Echinoidea) del Golfo De México.

The echinoid fauna of the Gulf of Mexico collected during three research cruises (20-1260 m depth) was surveyed from samples were taken at 43 stations. A total of 190 individuals were identified (eight orders, 11 families, 15 genera and 18 species). Six species are new records for the Gulf of Mexico: Stylocidaris lineata, Phormosoma placenta placenta, Plesiodiadema antillarum, Plethotaenia spatangoides, Brissopsis atlantica and Hypselaster limicolus. This adds to the little information available on the echinoid fauna of Tamaulipas, Veracruz, Tabasco, Campeche and Yucatan states in Mexico.

[Echinoderms (Echinodermata) of the Mexican Caribbean]. / Equinodermos (Echinodermata) del Caribe Mexicano.

A systematic list of the echinoderms of the Mexican Caribbean based on museum specimens of the Colección Nacional de Equinodermos, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México and the National Museum of Natural History, Smithsonian Institution, Washington, D.C. is presented. This list reveals an important echinoderm biodiversity in the Mexican Caribbean, where five of the six echinoderm classes are represented. A total of 178 echinoderm species is recorded, distributed in 113 genera, 51 families and 22 orders. 30 new records for the Mexican Caribbean are presents: Crínoidea (three), Asteroidea (two), Ophiuroidea (eleven), Echinoidea (one), Holothuroidea (thirteen).

[Echinoderms (Echinodermata) from the Gulf of California, Mexico]. / Equinodermos (Echinodermata) del Golfo de California, México.

A systematic list of the echinoderms of the Gulf of California, based on museum specimens of the Colección Nacional de Equinodermos, Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Autónoma de México and the National Museum of Natural History, Smithsonian Institution, Washington, D.C. is presented. A total of 193 echinoderm species is recorded, distributed in 108 genera, 51 families and 19 orders. 12 new records for the Gulf of California are presented: Asteroidea (four), Ophiuroidea (three) and Holothuroidea (five).